quagmire

A swampy, soggy area of ground.

That quagmire regularly ‘swallows’ caught-up hikers’ boots

Never did I see a more dreary and depressing scene. Miles on miles of quagmire, varied only by bright green strips of comparatively solid ground, and by deep and sullen pools fringed with tall rushes, in which the bitterns boomed and the frogs croaked incessantly: miles on miles of it without a break, unless the fever fog can be called a break.

A perilous, mixed up and troubled situation; a hopeless tangle.

The paperwork got lost in a quagmire of bureaucracy.

Those election results are a quagmire for any coalition except one of national union.

To embroil (a person, etc.) in complexity or difficulty.